End-fire millimeter wave antenna with dual-polarization filtering characteristic

Abstract

The invention discloses an end-fire millimeter wave antenna with a dual-polarization filtering characteristic, which comprises a horizontal polarization end-fire filtering antenna unit and a vertical polarization end-fire filtering antenna unit, and the horizontal polarization end-fire filtering antenna unit and the vertical polarization end-fire filtering antenna unit form a shared aperture to realize fusion. The end-on-fire structure has the remarkable advantages that firstly, compared with an edge-on-fire antenna, the end-on-fire antenna can provide a relatively balanced radiation characteristic in a more compact space, so that interference of a metal back shell in the terminal equipment on a radiation mode is effectively avoided, and the radiation efficiency and the performance stability of the antenna are remarkably improved; secondly, the design of the end-fire dual-polarization filtering antenna is realized by adopting a fusion mode, the integration performance of the antenna and a radio frequency front-end system is optimized, and the antenna has remarkable advantages in the aspects of reducing the size, improving the bandwidth, enhancing the anti-interference capability, improving the operation stability and the like; and a brand new technical scheme is provided for efficient operation of the radio frequency front end in the terminal equipment.

Description

Technical Field

[0001] The present invention relates to the technical field of millimeter wave antennas, and in particular to an end-fire millimeter wave antenna with dual-polarization filtering characteristics. Background Art

[0002] Dual-polarized antennas have attracted widespread attention in the field of millimeter-wave antennas due to their excellent performance and stability. Their main advantages include polarization insensitivity and the ability to suppress multipath interference in complex environments, so they are widely used in various scenarios. However, the metal backplane in handheld terminal devices often interferes with the gain of side-fired dual-polarized antennas, so end-fired dual-polarized antennas have gained more favor in this field. At the same time, considering the limited space of terminal devices, how to incorporate filtering structures into antenna design to save space and improve performance has become the focus of many experts and scholars.

[0003] With the advancement of technology, multiple high-performance dual-polarization filtering antenna solutions have been proposed one after another, but most of them are concentrated in the field of edge-fire dual-polarization antennas, which are usually based on microstrip patches or magnetoelectric dipole antennas, and realize dual-polarization design through mutually perpendicular feeding methods. The radiator of the edge-fire antenna is usually larger, so its design freedom is higher, which is convenient for integrating filtering structures. However, the radiator area of ​​the end-fire dual-polarization antenna is smaller, and the design freedom is relatively limited, so it is difficult to integrate the filtering structure into it. Therefore, antennas with end-fire design and dual-polarization filtering characteristics are not common. However, compared with the edge-fire dual-polarization filtering antenna, the end-fire dual-polarization antenna generally has more concentrated radiation characteristics and can effectively avoid the influence of the metal backplane on the radiation performance in the narrow space of the terminal device. Summary of the invention

[0004] The object of the present invention is to provide an end-fire millimeter-wave antenna with dual-polarization filtering characteristics, which has the advantage of balanced radiation characteristics.

[0005] To achieve the above object, the present invention provides the following technical solutions: an end-fire millimeter wave antenna with dual-polarization filtering characteristics, comprising a horizontally polarized end-fire filtering antenna unit and a vertically polarized end-fire filtering antenna unit, wherein the horizontally polarized end-fire filtering antenna unit and the vertically polarized end-fire filtering antenna unit constitute a shared aperture to achieve fusion;

[0006] The vertically polarized end-fire filtering antenna unit is composed of two dielectric substrates and two metal layers, which are a first metal layer, a first dielectric layer, a second metal layer, a second dielectric layer and a third metal layer stacked in sequence from bottom to top;

[0007] The third metal layer includes two-level metal strips and a metal plate etched with a complementary split resonant ring;

[0008] The horizontally polarized end-fire filtering antenna unit comprises a microstrip feed line and a grounded coplanar waveguide.

[0009] Preferably, the first metal layer includes a microstrip feed line for feeding the horizontally polarized end-fire filtering antenna unit, the second metal layer includes a metal ground etched with multiple filtering structures and a radiation patch of the vertically polarized unit, and the third metal layer includes a metal ground, a filtering structure and a radiation patch.

[0010] Preferably, two parallel-placed type-I parallel resonant cavities and parallel complementary open-ring resonant cavities are etched on the vertically polarized end-fire filter antenna unit and the second-layer metal ground structure to form an artificial surface plasmon structure, and the type-I parallel resonant cavity is provided with a vertical polarization opening and a horizontal polarization opening.

[0011] Preferably, the vertically polarized end-fire filtering antenna unit comprises a coaxial probe and a substrate integrated waveguide, wherein complementary open resonant rings are etched at the connection points between the coaxial probe and the substrate integrated waveguide ground plate, and a metal via is provided at the front end of the substrate integrated waveguide, and the metal via is offset inward.

[0012] Preferably, the front end of the vertically polarized end-fire filtering antenna unit is loaded with two-level metal strips, the two-level metal strips are located between the second metal layer and the third metal layer, and the two-level metal strips have different lengths, which are approximately a quarter of a wavelength.

[0013] Preferably, the front end of the inner conductor of the grounded coplanar waveguide is bent and connected to the ground plane, and a half-wavelength V-type dipole is arranged at the front end of the grounded coplanar waveguide.

[0014] Preferably, a complementary open ring resonant and an I-type parallel resonant cavity design is adopted on the metal floor of the second metal layer, and the lengths of the complementary open ring resonant and the I-type parallel resonant cavity are close to half the waveguide wavelength.

[0015] Preferably, a quarter-wavelength open-circuit branch is arranged in parallel at the connection between the microstrip feed line and the coaxial probe of the first metal layer, and the quarter-wavelength open-circuit branch is short-circuited near the radiation zero point.

[0016] Preferably, a parasitic microstrip open loop is added to the front end of the V-shaped dipole

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] 1. The present invention organically integrates the dual-polarization end-fire antenna and the filtering function structure through the antenna unit with dual-polarization filtering characteristics, and successfully realizes the design of end-fire millimeter-wave antenna with fusion dual-polarization filtering. Compared with the traditional dual-polarization antenna design, it not only optimizes the space utilization of the antenna, but also significantly improves the overall performance of the system, especially in terminal devices with limited space, greatly meets the dual needs of antenna performance and space saving, and is tightly integrated, which greatly reduces the volume and layout complexity of the antenna unit.

[0019] 2. Compared with the traditional method of using a side-fire method to implement a dual-polarization filter antenna design, the end-fire structure of the present invention has significant advantages. First, compared with the side-fire antenna, the end-fire antenna can provide a more balanced radiation characteristic in a more compact space, thereby effectively avoiding the interference of the metal back shell in the terminal device on the radiation mode, and significantly improving the radiation efficiency and performance stability of the antenna. Secondly, the end-fire dual-polarization filter antenna design is realized by a fusion method, which optimizes the integration performance of the antenna and the RF front-end system, and shows significant advantages in reducing volume, increasing bandwidth, enhancing anti-interference capability and improving operational stability, providing a new technical solution for the efficient operation of the RF front-end in the terminal device. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the structure of an end-fire antenna with dual-polarization filtering characteristics in a specific implementation manner of the present invention;

[0021] Figure 2 It is a schematic diagram of the structure of a horizontal polarization antenna unit and a vertical polarization antenna unit in a specific implementation manner of the present invention;

[0022] Figure 3 It is a plan view of the third metal layer of the dual-polarized antenna in a specific implementation manner of the present invention;

[0023] Figure 4 It is a plan view of the second metal layer of the dual-polarized antenna in a specific implementation manner of the present invention;

[0024] Figure 5 A plan view of the first metal layer of the horizontally polarized antenna unit in a specific embodiment of the present invention;

[0025] Figure 6 The impedance bandwidth and gain curve of the simulated horizontal polarization antenna unit with frequency in the present invention;

[0026] Figure 7 The impedance bandwidth and gain variation curve of the vertical polarization antenna unit simulated in the present invention with respect to the frequency;

[0027] Figure 8 It is the variation trend of the isolation between the horizontal polarization and the vertical polarization of the dual-polarization antenna unit in the present invention with frequency.

[0028] In the figure: 1. first metal layer; 2. first dielectric layer; 3. second metal layer; 4. second dielectric layer; 5. third metal layer; 6. horizontally polarized end-fire filter antenna unit; 7. vertically polarized end-fire filter antenna unit; 8. shared aperture; 9. coaxial probe; 10. substrate integrated waveguide; 11. metal via; 12. complementary open resonant ring; 13. artificial surface plasmon; 14. two-level metal strip; 15. vertically polarized opening; 16. microstrip feed line; 17. grounded coplanar waveguide; 18. I-type parallel resonant cavity; 19. parallel complementary open ring resonant cavity; 20. V-type dipole; 21. parasitic microstrip open loop; 22. quarter-wavelength open branch; 23. horizontally polarized opening. DETAILED DESCRIPTION

[0029] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] Example 1

[0031] like Figure 1 As shown, it is the first embodiment of the present invention, which provides an end-fire millimeter wave antenna with dual-polarization filtering characteristics, including a horizontally polarized end-fire filtering antenna unit 6 and a vertically polarized end-fire filtering antenna unit 7, and the horizontally polarized end-fire filtering antenna unit 6 and the vertically polarized end-fire filtering antenna unit 7 form a shared aperture 8 to achieve fusion;

[0032] The vertically polarized end-fire filtering antenna unit 7 is composed of two dielectric substrates and two metal layers, namely, a first metal layer 1, a first dielectric layer 2, a second metal layer 3, a second dielectric layer 4 and a third metal layer 5 stacked in sequence from bottom to top;

[0033] The third metal layer 5 includes two-level metal strips 14 and a metal plate etched with a complementary split resonant ring 12;

[0034] The horizontally polarized end-fire filtering antenna unit 6 includes a microstrip feed line 16 and a grounded coplanar waveguide 17 .

[0035] like Figure 1As shown, the antenna is stacked from bottom to top in sequence as a first metal layer 1, a first dielectric layer 2, a second metal layer 3, a second dielectric layer 4, and a third metal layer 5. The end-fire millimeter-wave antenna with dual-polarization filtering characteristics is composed of a vertically polarized end-fire filtering antenna unit 7 and a horizontally polarized end-fire filtering antenna unit 6. The two different polarization antennas realize a fusion design by sharing an aperture 8. The dielectric layer uses a Rogers 4003C dielectric substrate. The thickness of the two dielectric substrates is 1.519 mm and 0.2 mm respectively, the relative dielectric constant is 3.55, and the dielectric loss is 0.0022;

[0036] In the dual-polarized end-fire filter antenna, the horizontally polarized end-fire filter antenna unit 6 is fed by a microstrip feeder 16, and the vertically polarized end-fire filter antenna unit 7 is fed by a coaxial probe 9;

[0037] The dual-polarization end-fire filter antenna uses only two layers of dielectric substrate, realizing a simplified low-profile dual-polarization end-fire filter antenna design. Since the present invention mainly adopts the process design of patch plus metal via 11, the antenna has extremely low processing cost, and the antenna unit is easy to be integrated with the RF front-end circuit package.

[0038] Example 2

[0039] Reference Figure 2-5 , which is the second embodiment of the present invention, and this embodiment is based on the previous embodiment.

[0040] In this embodiment, the first metal layer 1 includes a microstrip feed line 16 for feeding the horizontally polarized end-fire filtering antenna unit 6, the second metal layer 3 includes a metal ground etched with multiple filtering structures and a radiation patch of the vertical polarization unit, and the third metal layer 5 includes a metal ground, a filtering structure and a radiation patch.

[0041] Two parallel-placed type I parallel resonant cavities 18 and parallel complementary open ring resonant cavities 19 are etched on the vertically polarized end-fire filtering antenna unit 7 and the second-layer metal ground structure to form an artificial surface plasmon 13 structure. A vertical polarization opening 15 and a horizontal polarization opening 23 are provided on the type I parallel resonant cavity 18.

[0042] The vertically polarized end-fire filtering antenna unit 7 includes a coaxial probe 9 and a substrate integrated waveguide 10. A complementary open resonant ring 12 is etched at the ground plate connection point between the coaxial probe 9 and the substrate integrated waveguide 10. A metal via 11 is provided at the front end of the substrate integrated waveguide 10, and the metal via 11 is offset inward.

[0043] like Figure 2-5As shown, by adjusting the width of the substrate integrated waveguide 10, that is, adjusting the spacing between some continuous metal vias 11 in the substrate integrated waveguide 10, the lower sideband cutoff frequency of the vertically polarized end-fire filter antenna unit 7 can be adjusted, and the lengths of the two type I parallel resonant cavities 18 artificial surface plasmon 13 structures can be adjusted separately, thereby adjusting the upper sideband cutoff frequency of the vertically polarized end-fire filter antenna unit 7, that is, etching two open circular rings with a width of 0.1 mm and different diameters on the metal ground of the substrate integrated waveguide 10, a radiation zero point can be introduced in the upper sideband and the lower sideband of the vertically polarized end-fire filter antenna unit 7, respectively, thereby enhancing the steepness coefficient.

[0044] Example 3

[0045] Reference Figure 1-8 , which is the third embodiment of the present invention, and this embodiment is based on the previous two embodiments.

[0046] In this embodiment, the front end of the vertically polarized end-fire filtering antenna unit 7 is loaded with a two-stage metal strip 14, which is located between the second metal layer 3 and the third metal layer 5. The two-stage metal strip 14 has different lengths, which are approximately a quarter wavelength.

[0047] The front end of the inner conductor of the grounded coplanar waveguide 17 is bent and connected to the ground plane, and a half-wavelength V-type dipole 20 is disposed at the front end of the grounded coplanar waveguide 17 .

[0048] The metal floor of the second metal layer 3 is designed with a complementary open resonant ring 12 and an I-type parallel resonant cavity 18 , and the lengths of the complementary open resonant ring 12 and the I-type parallel resonant cavity 18 are both close to the half-waveguide wavelength.

[0049] A quarter-wavelength open-circuit branch 22 is arranged in parallel at the connection between the microstrip feed line 16 of the first metal layer 1 and the coaxial probe 9, and the quarter-wavelength open-circuit branch 22 is short-circuited near the radiation zero point.

[0050] A parasitic microstrip open loop 21 is added to the front end of the V-dipole 20 .

[0051] like Figure 1-8As shown, in order to optimize impedance matching and enhance isolation between units, a microstrip feed line 16 and a grounded coplanar waveguide 17 are used. The grounded coplanar waveguide 17 structure of the horizontally polarized end-fire filter antenna unit 6 and the substrate integrated waveguide 10 structure of the vertically polarized end-fire filter antenna unit 7 share part of the metal via 11, thereby realizing a compact dual-polarized end-fire antenna with a shared aperture 8. The V-type dipole 20 is fed by surface wave coupling, thereby generating preliminary horizontally polarized radiation. These lengths can be optimized by simulation software, and at the same time, by adding a second dielectric layer 4, a complementary open resonant ring 12 and an I-type parallel resonant cavity 18 around The vertical polarization opening 15 and the horizontal polarization opening 23 form two parallel complementary open ring resonant cavities 19 with the second metal layer 3 and the third metal layer 5. The frequencies of the two radiation zero points can be independently adjusted by adjusting the total length of the complementary open resonant ring 12 and the length of the I-type parallel resonant cavity 18. The currents on the two microstrip feed lines 16 cancel each other out, thereby adding a radiation zero point in the low frequency band of the horizontally polarized end-fire filter antenna unit 6 to achieve a band-stop filtering function. The current on the parasitic microstrip open loop 21 near the radiation zero point and the current on the V-type dipole 20 reversely cancel each other out to achieve band-stop filtering in the lower sideband of the horizontally polarized end-fire filter antenna unit 6.

[0052] As attached Figure 6 As shown, the simulated impedance bandwidth and vertex gain variation curves of the horizontally polarized end-fire filtering antenna unit 6 with respect to frequency are given, and the horizontally polarized unit achieves a -10dB impedance bandwidth of 16% and an out-of-band gain suppression of 13dB.

[0053] As attached Figure 7 As shown, the simulated impedance bandwidth and vertex gain variation curves of the vertically polarized end-fire filtering antenna unit 7 with respect to frequency are given, and the vertically polarized unit achieves an impedance bandwidth of -10 dB of 18% and an out-of-band gain suppression of 11 dB.

[0054] As attached Figure 8 As shown, the curve of the isolation between adjacent units of the dual-polarization end-fire filtering antenna varying with frequency is given.

[0055] The standard parts used in this application document can all be purchased from the market and can be customized according to the description in the specification and drawings. The specific connection methods of each part adopt conventional means such as mature bolts, rivets, welding, etc. in the prior art. The machinery, parts and equipment all adopt conventional models in the prior art. The control method is automatic control through a controller. The control circuit of the controller can be implemented through simple programming by technicians in this field, which is common knowledge in the field. This application is mainly used to protect mechanical devices, so this application no longer explains the control method and circuit connection in detail.

[0056] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0057] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An end-fire millimeter-wave antenna with dual-polarization filtering characteristics, characterized in that: It comprises a horizontally polarized end-fire filter antenna unit (6) and a vertically polarized end-fire filter antenna unit (7), wherein the horizontally polarized end-fire filter antenna unit (6) and the vertically polarized end-fire filter antenna unit (7) form a shared aperture (8) to achieve fusion; The vertically polarized end-fire filtering antenna unit (7) is composed of two dielectric substrates and two metal layers, which are a first metal layer (1), a first dielectric layer (2), a second metal layer (3), a second dielectric layer (4) and a third metal layer (5) stacked in sequence from bottom to top; The third metal layer (5) comprises two-level metal strips (14) and a metal plate on which a complementary open resonant ring (12) is etched; The horizontally polarized end-fire filtering antenna unit (6) comprises a microstrip feed line (16) and a grounded coplanar waveguide (17).

2. The end-fire millimeter-wave antenna with dual-polarization filtering characteristics according to claim 1, characterized in that: The first metal layer (1) comprises a microstrip feed line (16) for feeding a horizontally polarized end-fire filtering antenna unit (6), the second metal layer (3) comprises a metal ground etched with a plurality of filtering structures and a radiation patch of a vertically polarized unit, and the third metal layer (5) comprises a metal ground, a filtering structure and a radiation patch.

3. The end-fire millimeter-wave antenna with dual-polarization filtering characteristics according to claim 1, characterized in that: Two parallel-placed type I parallel resonant cavities (18) and parallel complementary open-ring resonant cavities (19) are etched on the vertically polarized end-fire filtering antenna unit (7) and the second metal ground structure to form an artificial surface plasmon (13) structure; the type I parallel resonant cavity (18) is provided with a vertical polarization opening (15) and a horizontal polarization opening (23).

4. The end-fire millimeter wave antenna with dual-polarization filtering characteristics according to claim 1, characterized in that: The vertically polarized end-fire filtering antenna unit (7) comprises a coaxial probe (9) and a substrate integrated waveguide (10), wherein a complementary open resonant ring (12) is etched at a ground plate connection point between the coaxial probe (9) and the substrate integrated waveguide (10), and a metal via (11) is provided at the front end of the substrate integrated waveguide (10), wherein the metal via (11) is offset inward.

5. The end-fire millimeter wave antenna with dual-polarization filtering characteristics according to claim 1, characterized in that: The front end of the vertically polarized end-fire filtering antenna unit (7) is loaded with a two-stage metal strip (14), the two-stage metal strip (14) is located between the second metal layer (3) and the third metal layer (5), and the two-stage metal strip (14) has different lengths, which are approximately a quarter wavelength.

6. The end-fire millimeter-wave antenna with dual-polarization filtering characteristics according to claim 1, characterized in that: The front end of the inner conductor of the grounded coplanar waveguide (17) is bent and connected to the ground plane, and a half-wavelength V-shaped dipole (20) is arranged at the front end of the grounded coplanar waveguide (17).

7. The end-fire millimeter wave antenna with dual-polarization filtering characteristics according to claim 1, characterized in that: The metal floor of the second metal layer (3) is designed with a complementary open resonant ring (12) and an I-type parallel resonant cavity (18), and the lengths of the complementary open resonant ring (12) and the I-type parallel resonant cavity (18) are both close to half the waveguide wavelength.

8. The end-fire millimeter wave antenna with dual-polarization filtering characteristics according to claim 1, characterized in that: A quarter-wavelength open-circuit branch (22) is arranged in parallel at the connection between the microstrip feed line (16) of the first metal layer (1) and the coaxial probe (9), and the quarter-wavelength open-circuit branch (22) is short-circuited near the radiation zero point.

9. The end-fire millimeter wave antenna with dual-polarization filtering characteristics according to claim 6, characterized in that: A parasitic microstrip open loop (21) is added to the front end of the V-shaped dipole (20).

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